Pump



PUMP

Original Filed July 19, 1929 :EEQL.

lnfl'enzor 077 07226625 27. Gard 726 7 Patented Aug. 14, 1934 UNITED STATES PATENT OFFICE Application July 19, 1929, Serial No. 379,334 Renewed January 8, 1934 2 Claims. (Cl. 103-96) This invention relates to pumps, and particularly to pumps which are especially adapted for supplying fuel to the carburetors of internal combustion engines, the principal object being the 5 provision of a new and novel construction that will be economical to manufacture and eificient in use.

Another object is to provide a pump of the type described in which there is but a single moving part, and that limited to rotary movement, and in which the intake and the outlet to the pumping chamber are both disposed at the periphery of the rotating element.

Another object is to provide a pump of the class described so constructed that it will never lose its prime.

Another object is to provide a pump of the class described including a rotor formed to provide a priming pocket.

Another object is to provide means cooperable with a mechanical fuel pump disposed between the fuel supply tank and the carburetor for an internal combustion engine, which will prevent complete draining of the fuel line upon exhaustion of the supply of fuel in the tank.

Another object is to provide, in combination with a mechanical fuel pump for supplying fuel to the carburetor of an internal combustion engine, a signal means for smoothing out pulsations in the discharge line from-the fuel pump and for providing a priming charge for the pump when the pump is stopped.

Another object is to provide a pump of the class described comprising a single rotating element having a serrated surface and tangentially disposed inlet and outlet passages leading to and from said surface.

A further object is to provide a simple and economical fuel pumping means of novel construction for supplying fuel to the carburetor of an internal combustion engine.

The above being among the objects of the present invention, the same consists in certain features of construction and combinations of parts to be hereinafter described with reference to the accompanying drawing, and then claimed, having the above and other objects in view.

In the accompanying drawing which shows a suitable embodiment of the present invention, and in which like numerals refer to like parts throughout the several different views;

Fig. 1 is a vertical sectional view taken through a fuel pump as on the line 11 of Fig. 2.

Fig. 2 is a vertical sectional view taken on the line 2-2 of Fig. 1.

Fig. 3 is a more or less diagrammatic view showing the relative position of the fuel pump with respect to the fuel tank and the carburetor for an internal combustion engine.

The present invention has for its primary object the provision of a simple and eflicient mechanical pump for supplying fuel to the carburetor of an internal combustion engine, and one that will be economical to manufacture. In view of the lubricant-destroying qualities of the fuel employed for internal combustion engines of the type commonly employed in connection with motor vehicles, the attempts to provide a mechanical pump for supplying the fuel to the carburetor of such engines have not met with particular success in the past, without resorting to necessarily expensive constructions. In view of the problems involved in connection-with such pumps, it has been my theory that in order to be commercially successful such a pump must have a minimum of bearing or wearing surfaces, and accordingly the pump provided in accordance with the present invention has preferably but a single bearing.

Also, in view of the fact that the fuels usually employed in connection with the carburetors for internal combustion engines are extremely fluid, it is extremely difficult, particularly in quantity production, to maintain the limits of dimensions on various parts to within such close limits as to insure the pump holding its prime over an extended period of inoperation. It is extremely desirable that such pumps do not lose their prime, for when the prime is once lost it usually requires that the engine be turned over rapidly for an appreciable length of time, in order to again establish a flow of fuel through the pump. In cold weather, where a mechanical pump for supplying fuel to an internal combustion engine has lost its prime, it is often impossible to rotate the engine fast enough to re-establish the flow of fuel, and furthermore, it is liable to cause the battery to be exhausted of its energy. The present invention provides a construction wherein the dangers of losing the seal in the pump are completely eliminated.

Referring to the accompanying drawing, I show a pump comprising a casing 10 having therein a circular recess 11 closed by a cap 12. The casing 10 is provided with an extension 13 in which the 105 shaft 14 has bearing, the shaft 14 extending axially into the recess 11 in concentric relation therewith. Within the recess 11 and secured against rotation to the shaft 14 by any suitable means such as a key 15, is a rotor 16. The periphery of no 2 the rotor 16 extends into closely adjacent but preferably non-rubbing relation with respect to the circular walls of the recess 11 and its periphery is provided with a plurality of serrations or pockets such as 17. These pockets may take any suitable form desired, but are preferably of a size to contain a substantial volume of fuel therein. The rotor '16 is of awidth substantially to fill the depth of the recess 11, or, when end wear plates such as 18 and 19 are provided in the ends of the recess for possible contact with the opposite sides of the rotor 16, the rotor 16 is of such a' width as to fill the space between the plates 18 and 19. These plates may be of bronze, fiber, or other suitable material. I

The-casing 10 is provided with an inlet passage 20 preferably positioned vertically as indicated in Fig. 1, the lower end of which is connected by the ports 2l with the recess 11. These ports 21 may be plural as shown, or may bemerely a single port where desired. These ports are so shaped that the fuel from the passage 20 passing through the ports, will enter the recess 11 in a direction tangential to the periphery of the rotor and in the direction of rotation of the rotor 16 (indicated by the arrow 22 in Fig. 10) The casing 10 is also provided with an outlet passage 23 connected to the recess 11 through one or more ports 24. These ports 24 are likewise arranged in approximately tangential relationship with respect to the periphery of the rotor and so that the liquid discharged through them is discharged from the periphery of the rotor 16 in the direction of rotation thereof. The passageway 23 is likewise preferably vertically positioned.

The inlet passage 20 is closed by an apertured fitting 25 and a check valve 26 urged by the coil spring 27 against the lower end of the fitting 25 serves to seal the pump against reversal of flow of fuel through the fitting 25. The passageway 28 connects the passageways 20 and 23 and is en larged as at 29 to provide a shoulder 30 for the check valve 31 which is urged against the seat 30 by the coil spring 32. The tension of the coil spring 32 may be controlled through the adjustable plug 33. It will be evident that the check valve 31 will open when a predetermined discharge pressure exists in the discharge passage 23 and will then by-passthe fuel from the outlet to the inlet passages so as to limit the maximum pressure which may be built up by the pump, and which maximum pressure may be controlled by suitably controlling the axial position of the plug 33.

The pump will, of course, normally be positioned above the gasoline tank 40 and below the bowl 41 of the carburetor 42. Because of the fact that the tank 40 is'below the pump, if the seal of the pump is once broken it might be rather diflicult, particularly in view of the type of the pump, to establish a suflicient suction within the pump to again lift the fuel from the tank to the pump without unnecessary delay. For this reason it is particularly important that means be provided for preventing the seal of the pump from being broken. The check valve 26 will normally prevent the fuel from reversing its flow between the pump and the tank 40. It will be apparent that should the pumping operation be continued until the fuel in the tank 40 is exhausted and all the fuel in the suction line has been forced through the pump to the carburetor side of the pump, there might be an insufficient amount of fuel left in the pump to establish a sufficient seal to insure the pump again re-establishing the flow from the fuel tank: In order to overcome any possibility of such an occurrence, the following construction is provided.

Connected to the outlet passage 23 either directly as shown, or by a separate pipe, is a base member 43 having secured thereto and sealed against leakage an inverted cup-shaped metallic bellows 44. The base. 43 is provided with a passage 45 connecting the passage 23 with the bottom of the space within the bellows 44. A stand pipe 46 is secured to the base 43 within the bellows and its upper end terminates short of the top wall of the bellows. The interior of the stand pipe 46 is connected by the tube 47 to the bowl 41 of the carburetor 42.

In operation, the fuel discharged from the pump first fills the interior of the bellows 44 until it overflows the top of the stand pipe 46, after which it passes down through the stand pipe and tube 47 to the carburetor. In conjunction with the bellows 44 and stand pipe 46 I provide another fuel reservoir which takes the form of pockets 48 formed in the ends of the rotor 16. The radially outward wall of these pockets 48 extends outward both axially and radially from adjacent the center of the hub in the rotor 16 and merges into the plane of the end walls of the rotor adjacent the periphery thereof so as to leave only a slight possible area of contact between the end surfaces of the rotor and the corresponding end surfaces of the recess 11, or plates 18 and 19, as the case may be.

In operation, any fuel that may have collected in the pockets 48 is thrown by centrifugal action to the periphery of the pockets 48 and eventually finds its way to the periphery of the rotor 16, thus emptying the pockets 48. As soon as the pump is stopped the fuel in the bellows 44 will tend to run back through the passage 23 into the recess 11, and in so doing, this fuel will fill'the' pockets 48, which are preferably constructed to provide a combined volume substantially equal to that of the fuel normally trapped in the bellows 44. It will be apparent that with this construction, the moment that the pump is again rotated, this fuel caught within the pockets 48, in being thrown to the periphery of the rotor 16, will again seal the pump.

It will also be apparent that because of the reservoir of fuel in the bellows 44 which can never be reduced or carried on to the carburetor, that no matter if the tank 40 is run dry until no more fuel is pumped to the carburetor, the moment the pump stops the fuel in the bellows 44 will return to the pump and be ready to seal the pump as soon as the pump is again operated, and that this amount of fuel and consequently the seal can never be lost. This sealing effect is, of course, aided by bringing the inlet and outlet passages for the recess 11 out of the pump adjacent the top of the same and above the upper limit of the recess 11.

It will be apparent that as far as the operation of the device so far described is concerned, the bellows 44 may be replaced by a rigid inverted cup-shaped member which will function exactly in the same manner as described in connection with the bellows 44, and it is to be understood that this phase of the present invention is not limited to the use of a bellows in this-position. The reason that this member is shown as a bellows is that a bellows, by expanding or contracting, will act to smooth out any pulsations that might occur in the flow of fuel, and furthermore during operation of the pump while the bellows is under the discharge pressure of the fuel from the pump, it tends to expand and therefore hold a greater reserve of fuel for discharge back into the pump when the pump is stopped and the pressure on the bellows relieved. If desired, any conventional form of filtering or settling chamber may be incorporated in connection with the base 43. The construction of the same may be similar to that of any of the conventional forms of filtering and settling chambers now on the market.

The pump mechanism heretofore described may be supported and driven in any suitable manner, such as that shown in connection with Fig. 2, which illustrates the pump mounted upon a crank case 50 of an internal combustion engine. The particular manner of mounting shown comprises screws such as 51 extending through flanges 52 formed on the pump casing, an opening such as 53 being provided in the crank case wall for inserting the extended portion 13. The end of the shaft 14 within the crank case 50 is provided with a gear 54 which is shown in meshing re lationship with the gear 55 on the cam shaft 56 in order to receive driving movement therefrom. If desired, the shaft 14 may be provided with an outboard bearing such as 57 and a thrust washer such as 58 may be positioned on either side of the gear 54 in order to lock the gear 54 and therefore the shaft 14 and rotor 16 against axial movement.

Lubrication of the shaft 14 and sealing of the shaft bearing against leakage of fuel from the recess 11 may be effected by providing an oil lead 59 in the extension 13 which is adapted to collect the oil and lead it to the shaft 14 adjacent the outer thrust bearing 58, and by providing a spiral groove such as 60 in the shaft 14 which is adapted to receive the oil from the duct 59 and carry it along the shaft towards the recess 11 to a point such as an annular groove 61 formed in the bearing for the shaft 14 adjacent the recess 11. The shaft 14 in rotating will carry the oil towards the recess and deposit it in the groove 61 which will thus seal the shaft against leakage of the fuel along the shaft 14 and also provide ample lubrication for the same.

While I have shown a particular construction in the drawing as illustrative of the present invention, it will be apparent that it may be subjected to various modifications and changes without materially modifying the invention involved therein, and formal changes may be made in the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

1. In combination, a mechanical fuel pump, a carburetor, and a duct connecting said fuel pump and carburetor, means in open communication with said duct and in draining communication with said pump for trapping a substantial volume of fuel between said pump and said carburetor against passage to said carburetor during operation of said pump, a casing for said pump having a cylindrical recess therein and a rotor in said recess in substantial contact 'with substantially the entire circumference of said recess and in substantial contact with both end walls thereof, the ends of said rotor being formed to provide pockets for the reception of said trapped fuel upon stopping of said pump.

2. In combination, a pump for liquid comprising a casing having a circular recess therein, a peripherally pocketed rotor concentrically mounted in said recess, the periphery and adjacent side edges of said rotor lying at all times in substantial contact with the corresponding walls of said recess, an inlet and outlet for said recess leading to and from the periphery of said rotor, said rotor being hollowed out on the sides thereof to form a reserve space for the liquid being pumped when said pump is not in operation, a carburetor, a duct connecting said outlet and said carburetor, and a chamber in open communication with said duct and in draining relation with said pump, for trapping an amount of liquid substantially equal to said reserve space from passing to said carburetor.

ARCHIBALD D. GARDNER. 

